An advance in the construction of spas has been the development of modular construction systems that allow for easier upgrading and repair of water jet systems in a spa. These modular systems are disclosed in U.S. Pat. No. 5,754,989, issued 26 May 1998, titled “PLUMBING AND SHELL SYSTEM FOR SPA”; U.S. Pat. No. 6,092,246, issued 25 Jul. 2000, titled “PLUMBING AND SHELL SYSTEM FOR SPA”; U.S. Pat. No. 6,000,073, issued 14 Dec. 1999, titled “JET ZONE DISTRIBUTION SYSTEM FOR SPAS”; U.S. Pat. No. 5,987,663, issued 23 Nov. 1999, “MODULAR SYSTEM FOR SPAS AND BATHING SYSTEMS”; U.S. Pat. No. 6,256,805, issued 1 Jul. 2001, titled “MODULAR SYSTEM FOR SPAS AND BATHING SYSTEMS”; and U.S. Pat. No. 6,543,067, issued 8 Apr. 2003, titled “INTEGRATED MANIFOLD SYSTEM FOR SPAS”. These patents provide background, and are hereby incorporated by reference.
In these modular systems a shell is constructed with depressions or hollows in the shell wall. Each of the hollows is fitted with a modular unit, here referred to as a modular unit (also called JetPak™). The modular unit comprises a cover for the hollow upon which are mounted jets for injecting water into the spa containment. A water inlet line extends through the shell to provide a water supply for the jets. To remove the jets (for replacement, repair, or for an upgrade to different jets), the water supply lines for the jets are disconnected from the water supply and the cover is removed. To allow disconnecting of the water inlet line from the modular unit, a manifold is provided that has unions for disconnection and reconnection to the water inlet line. The manifold also has ports for water supply lines to multiple jets, and an air supply manifold with ports for air supply lines to the jets.
The water supply system of the spa comprises one or more water inlet lines with multiple modular units connected through their respective manifolds in series along a water supply line. The supply line usually enters the hollow above the water line, which eases access to the manifold. The water inlet line enters the hollow and is connected to the manifold through the union. A water exit is usually provided through a union connection to the manifold and a water line that becomes the water inlet line for the next modular unit in the water supply circuit.
This modular system has several advantages, including the ability to upgrade, replace, interchange, or customize the jet system without destructive alteration of the shell. In addition, the joints at which water leaks are likely to occur are in regions that communicate with the shell water containment. Accordingly, most leaks are benign, which contrasts with traditional spa designs where all of the water supply is under the spa shell, and almost any leak will discharge water into insulation under-the shell and on the floor under the spa.
While the modular spa systems have many advantages, there are yet some difficulties. The water supply system of the modular spa is comparatively complex since each modular unit must include an assembly of a manifold with sealing connections to inlet and outlet water lines, several separate water lines from the manifold to each jet, and several air lines from an air supply manifold. This complexity and multiplicity of parts leads to higher manufacturing costs for the materials and higher labor cost in the assembly.
A simplified construction that provides the advantages of a modular spa, but has a simpler construction and is less expensive to build would be an advance in the art.